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Topic: my robot fish, revealed! (Read 21785 times)

For almost two years now Ive been asking weird questions on the forum to get help for my big robot fish project. But unfortunately, being a government project, I wasn't allowed to reveal the details . . . until now!

I wrote up a big 8 page science paper on it, and submitted it to ICRA (International Conference on Robotics and Automation). In all, ICRA recieved 1800 papers covering all types of robotics research.

Yet despite this being the first paper I ever wrote, out of that 1800 papers it was given the 'Best Conference Paper Award' - so its bound to be a good read

I wonder how a flexible articulated tail fin like that would do... I think you would need the articulation on a different axis, but it may be that being able to independently articulate the top and bottom of the fin from the center would produce more thrust.

That is insanely wicked. It's a pretty neat concept, I only wish I could get into stuff like that right now. Unfortunately, I'm 16 and the most that a program can offer is playing with LEGO mindstorms, which I own too much at. I had that at like 10.

It's a very good paper. I hope to do stuff like this in the future, I'm interested in seeing the next paper.

The first paper was designing and studying a robot fin. This paper however covers how to control a vehicle with flapping fins. Unlike with traditional propellor thrusters that give predictable steady thrust in a single direction, flapping fins gives crazy thrusts in many different directions. No one has ever figured out how to control a UUV (unmanned underwater vehicle) with pectoral fins that can change shape, until now.

I wouldnt say its a 100% solved problem, but its definitely an advancement.

Warning - being a controls paper, it is heavy in math and derivation. But being a 2nd author on the paper I can promise you nice CAD models of the design and my own personal touch.

Isn't it kinda crazy that is seems controllable with PID?I would have thought some crazy calculus + fuzzy logic would be optimal... I guess that's why I'm putting in my apprenticeship (so to speak) in a control oriented field

For those who like math and controls, there's lots of it. For those who don't, there are lots of pictures of my robot fish

So why does it take forever to post stuff on my fish? Well, because science is sloooowwwwwww. From inception of a theory to experimentally proving it takes about a year. Then another ~3 months to write a paper on it. Then another ~2-4 months until it is accepted by a journal or conference.

I currently have three more papers in the works, one 95% done, one 60% done, and the last 10% done. I got good results and am mostly finished, but it will take another ~6 months to get it all published.

HeyI like that second paper (not to take away from the first paper, but I am a controls guy).

The idea of having the fuzzy logic stage after the main PID controller is interesting. I'm thinking that I can adapt that to a slow moving wheeled rover. The rover has just two ticks per revolution on each wheel which makes it difficult to implement a smooth constant velocity controller that works while going over obstacles or other "features".

My idea is after the PID stage I can add a "fuzzy" stage where I compensate for changes in acceleration and rover pitch.(I don't plan on publishing this control work, but if I do Ill reference you)

Ok so its been like a year since I've reported anything new on this project. Well, its because I traveled 8 months around the world (mostly Thailand), so didn't get to work on anything. Below you'll find two new papers recently published. Three more are in the pipeline, hopefully getting published by early next year.

Its heavy reading, lots of controls, CFD stuff, fluid mechanics, etc. I do however strongly recommend looking at the pics. And yeap, pics of the prototype fish swimming around in water!

This following paper models the robot fish in CFD to determine drag coefficients and the effects of the fish body on the fins. This is a 5mb file.

It's been forever since my last post, and I'm still working hard on that video I've promised to upload, but here is another paper with pretty pictures to hold you guys off a bit longer. It covers CFD simulations and analysis of the pectoral fin and chassis.

Here is a CFD analysis of the latest fish design. Lots of pretty pics if you don't like reading. I'll probably have another paper posted up in the coming weeks. Maybe, just maybe, I'll have a video for you guys by Christmas.